These also happen to be the only columns of type "double" in mysql. And, they are the only columns defined in the XMLDB XML as type "float" with no DECIMALS attribute set. (Try: find -name "install.xml" | xargs -i grep -H 'TYPE="float"' {})

Things appear to go wrong in get_columns in lib/dml/mysqli_native_moodle_database.php at this line: